FYI - The Electric Yacht Quiet torque 20 uses two Motenergy ME 1115 motors. The QT 30 uses two Motenergy ME1616 motors. The 1616 is water cooled, the 1115 is not.
If you have the power reserve available, whether it is more batteries, a gen set, or a flux capacitor, and you want to be able to sustain high output levels, the motor will need cooling. The ME1115 is 10kW but that is a max burst rating NOT continuous. These are the motor ratings with and without cooling (from Motenergy)
ME1115 max continuous current 125 amps @48V = 6,000 Watts
ME1115 max continuous current 150 amps @48V = 7,200 Watts *
ME1507 max continuous current 160 amps @48V = 7,680 Watts
ME1616 max continuous (w/o cooling) 140 amps @48V = 6,720 Watts
ME1616 max continuous (w cooling) 250 amps @48V = 12,000 Watts
* different rating from Motenergy web site
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Montenergy email 11/2020:
1) The ME1304 is rated for 200 amps continuous with
water cooling, and 125 without water cooling.
2) The ME1616 is rated for 140 amps continuous without
water cooling. This is a lower specification as compared
to the ME1507, because the ME1507 has cooling fins on
the external case, and the case is thinner, in direct
contact with the windings and laminations.
3) We rate the ME1616 motor at 2 minutes, 600 amps.
This is form a cold start. If the motor is already at
maximum temperature, then this time and maximum
current will be lower.
The ME1115 is good for about 125 amps, 1/2 the
continuous power as compared to the ME1616.
Both will run the same speed with 48 VDC.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This means that without cooling the QT20 max output is 12,000 watts, NOT 20,000.
If you need to sustain higher output levels you need cooling. The best choice for that is a liquid cooled motor like the ME1616.
Regarding the original post seeking recommendations for a C&C 40, I don't know which C&C 40 this is but the displacement probably dials in around 8 to 10 tons? I think a water cooled ME1116 could handle this with your higher voltage installation plan but I agree with the comments about sticking to 48V. At 48V I don't know if it would have enough power to get you to hull speed. The prop match is VERY important for this. Spend some time on that.
My single ME1616 replaced a 23 HP diesel (Volvo) and it is better in every respect accept range.
Regarding Uma, they had a fixed prop with their original fork lift motor fabrication and had (4) lead acid deep cycles (this is way back when they started). I think their performance was OK except for range which was abysmal. Quite unrealistic capacity for typical use. Maybe 50AH of usable capacity? They were OK with that because the had time. Nice. Wouldn't work for most of us and I recall one episode where they were transiting the Miami river an had to find a municipal dock to recharge part way along. They upgraded to a bank of maybe 12 Battle Born LiFePo4 (a $10K battery bank?) and then they had practical range to get in/out of harbors and do actual motoring rather than be basically like having a trolling motor with a car battery. They later upgraded to Ocean Volt with their Servo Prop. Very nice unit with practical regen capacity.
Regarding Regen, I have regen with an 18" prop and while it does work it is not a practical power source for the way I use my boat (mostly day-sailing). The best I have been able to achieve is maybe 400 watts in sailing conditions were I could sustain 6.5 knots (33 ft/10M boat). And even then it required careful and active manipulation of the throttle to get it to work well. OceanVolt handles that part with a microprocessor. and I think Uma achieved maybe 500 watts max but more typically 250 to 300? Not sure and they are a little vague on presentation of data. Maybe it's better behind their pay wall. But I think a bigger boat would be more reliably capable of regen. Maybe a 9 ton 40 footer is above the threshold where practical regen is possible? I would definitely want it as an option. For me I can get better charging from solar.
I used the Thunderstruck 12kW liquid cooled kit (ME1616) but I built my own reduction unit (3:1 toothed belt drive). They were very helpful in the process. Now I am having trouble with their BMS and I need to contact them about that. I expect they will be helpful about that as well. I have a cooling plate on the controller that fluid circulates through. In my normal operation (motoring at 4.5 to 5.5 kts) I am at about 3500 watts max and do not need to engage cooling. If I want to power up to 6+ knots I need the cooling. I have 3 stages. First is turning on the coolant pump (Prius type pump) and fluid runs through the motor, controller, a raw water heat exchanger and a air heat exchanger (Ford Taurus heater core). 2nd stage turns on a fan on the air heat exchanger. 3rd stage turns on the pump on the raw water heat exchanger.
See details on my installation here:
http://dan.pfeiffer.net/10m/electric_drive.htm
Dan Pfeiffer
Good post and information!The QT are BLDC not PMAC, so wouldn't that make them quite a bit louder?What about the QT LC is better than the Thunderstruck with your addition of EZkontrol?Any thoughts on QT LC 15 vs the 20 which isn't LC (I think)? They're about the same cost...
On Wed, 4 June 2025, 1:05 am gsxbearman via groups.io, <gsxbearman=yahoo.com@groups.io> wrote:Recommendations? Yohoo! Essay time!
First the disclaimer. I am not an expert. I do not know it all, and am always willing to learn something new. I do have strong opinions on just about anything so if you ask, be prepared for an answer you may not agree with.
OK, since you said budget build, I will assume you are talking about the cheapest DIY system that meets your requirements of around 12KW and 48V.
I'm going to recommend the Thunderstruck ME1616 motor with the Thunderstruck 12-24KW Gear Reduction set from Thunderstruck-ev.com. But for a controller I would recommend an EZkontrol Motor controller from Goldenmoter.bike. Both sites have cooling water components. All in this is going to set you back $4-5k US$ (or more).
If you had said easiest, for your 40' boat, for $10k I would go with the Electric yacht QuietTorque 15.0 LC Electric Motor (the LC apparently means liquid cooled). I think it uses the same motor and comes with almost everything; a throttle, display, and output shaft mounted water pump.
For either of the above I would recommend a fresh water closed loop cooling system, for that you will also need to get a radiator with fan, or a heat exchanger with separate raw water pump.
Now for the why.
The ME1616 is a water cooled PMAC motor that uses sinusoidal wave form control, which is quieter than a BLDC motor that uses square (or trapezoidal) wave form control. I can run at 550 Amps for 1 minute (28kW at 51.2V) and 250 Amps continuous (12.8kW at 51.2V)
Water cooling is important for just about any boat application. The controller will overheat way before the motor.
The controller I recommended is a water cooled version and while you can not change the voltage, you can change practically every other setting on it. And you can set it to run sine wave or square wave motors. For your boat I recommend the EZ482000, It is capable of 1000 Amps (2000 is the phase amps). It is 4" longer than the EZ481200 (600Amps) and it will run cooler at any Amp rate you run it. And it's only about $200 more, so my thinking is spend the extra and only buy it once.
The gear reduction unit uses a 1" cog belt and pulleys that can be bought many places to change the gear ratio if needed, for your boat I would recommend getting the largest ratio to start with.
If I were in your shoes I would go with the Electric yachts QuietTorque 15.0 LC.
Yes it's double the money (but still way cheaper than a comparable diesel) and saves so much headache it's not even funny. And it has a 3 year warranty.
And no, I am not affiliated with, work for, or get commissions from ANY companies or web sites mentioned above (or anywhere else, I don't work in the EV or marine industry).
No comments:
Post a Comment